Human-disturbed landscapes: effects on composition and integrity of riparian woody vegetation in the Tagus River basin, Portugal

2005 ◽  
Vol 32 (1) ◽  
pp. 30-41 ◽  
Author(s):  
FRANCISCA C. AGUIAR ◽  
MARIA TERESA FERREIRA
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Environmental Factors ◽  
Human Disturbance ◽  
Riparian Vegetation ◽  
Woody Vegetation ◽  
Small Scale ◽  
Riparian Ecosystems ◽  
Average Width ◽  
The Impact

Human activities within fluvial corridors and surrounding landscapes have persistently stressed riparian ecosystems, particularly in Iberian Mediterranean-type streams. The impact of human disturbance relative to natural environmental factors in shaping riparian vegetation is still poorly understood. Both regional variables (such as altitude and precipitation), and site-specific characteristics (such as substrate and riverbank modifications) were analysed as potential determinants of riparian vegetation patterning to determine the relative influences of the diverse land-use types and environmental factors on the composition (including floristic species richness and percentage cover of trees, shrubs and woody climbers) and integrity (width of riparian woods and patterns of longitudinal continuity) of riparian woods in eight river basins of the Tagus fluvial system (Portugal). There was patchy establishment of riparian woods, with generally low average width and low species richness, as well as significant inter-basin differences and upstream-downstream variations in riparian features. Species distribution was clearly determined by environmental factors, such as human disturbance on the riverbanks and geological background, and the environmental variables and the land use in the river valley partially explained the integrity of riparian woody vegetation. The results highlight the predictive capability of reach-level features; it appears that, linked with the geomorphological and climate context, small-scale human disturbances on riparian corridors play a major role in explaining the remaining biological variability.

scholarly journals Estimating the potential biodiversity impact of redeveloping small urban spaces: the Natural History Museum’s grounds

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3914
Author(s):  
Helen R.P. Phillips ◽  
Sandra Knapp ◽  
Andy Purvis
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Natural History ◽  
Species Density ◽  
Urban Setting ◽  
Small Scale ◽  
Ecological Data ◽  
Current Form ◽  
Habitat Area ◽  
The Impact

Background With the increase in human population, and the growing realisation of the importance of urban biodiversity for human wellbeing, the ability to predict biodiversity loss or gain as a result of land use change within urban settings is important. Most models that link biodiversity and land use are at too coarse a scale for informing decisions, especially those related to planning applications. Using the grounds of the Natural History Museum, London, we show how methods used in global models can be applied to smaller spatial scales to inform urban planning. Methods Data were extracted from relevant primary literature where species richness had been recorded in more than one habitat type within an urban setting. As within-sample species richness will increase with habitat area, species richness estimates were also converted to species density using theory based on the species–area relationship. Mixed-effects models were used to model the impact on species richness and species density of different habitat types, and to estimate these metrics in the current grounds and under proposed plans for redevelopment. We compared effects of three assumptions on how within-sample diversity scales with habitat area as a sensitivity analysis. A pre-existing database recording plants within the grounds was also used to estimate changes in species composition across different habitats. Results Analysis estimated that the proposed plans would result in an increase of average biodiversity of between 11.2% (when species density was modelled) and 14.1% (when within-sample species richness was modelled). Plant community composition was relatively similar between the habitats currently within the grounds. Discussion The proposed plans for change in the NHM grounds are estimated to result in a net gain in average biodiversity, through increased number and extent of high-diversity habitats. In future, our method could be improved by incorporating purposefully collected ecological survey data (if resources permit) and by expanding the data sufficiently to allow modelling of the temporal dynamics of biodiversity change after habitat disturbance and creation. Even in its current form, the method produces transparent quantitative estimates, grounded in ecological data and theory, which can be used to inform relatively small scale planning decisions.

scholarly journals A Model-Based Tool for Assessing the Impact of Land Use Change Scenarios on Flood Risk in Small-Scale River Systems—Part 1: Pre-Processing of Scenario Based Flood Characteristics for the Current State of Land Use

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner
Keyword(s):  
Land Use ◽  
River Flow ◽  
Land Use Changes ◽  
Small Rivers ◽  
Small Scale ◽  
Model Parameters ◽  
Ungauged Catchments ◽  
Model Based ◽  
Current State ◽  
The Impact

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.

Monitoring of small rock pools reveals differential effects of chronic anthropogenic disturbance on birds and mammals in the Calakmul region, southern Mexico

2021 ◽  
pp. 1-10
Author(s):  
Carlos M. Delgado-Martínez ◽  
Fredy Alvarado ◽  
Melanie Kolb ◽  
Eduardo Mendoza
Keyword(s):  
Species Richness ◽  
Anthropogenic Disturbance ◽  
Forest Cover ◽  
Biosphere Reserve ◽  
Bird Diversity ◽  
Small Scale ◽  
Rock Pools ◽  
Southern Mexico ◽  
Wildlife Species ◽  
The Impact

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.

scholarly journals Spatial pattern of riparian plants along stream order among mountain rivers in China

2018 ◽  
Vol 9 (2) ◽  
pp. 322-330
Author(s):  
Rong Sun ◽  
Xiaojie Luo ◽  
Xiangyu Meng ◽  
Yan Wang
Keyword(s):  
Species Richness ◽  
Environmental Factors ◽  
Tree Species ◽  
Riparian Vegetation ◽  
Stream Order ◽  
River Continuum ◽  
Riparian Plants ◽  
Tree Species Richness ◽  
Riparian Species ◽  
Significant Difference

Abstract The streams in a watershed form a hierarchical network system. From the perspective of the river continuum, this classification system is the result of gradual increase in traffic. This study analyzed the riparian species richness, diversity and environmental factors along a six-order hierarchical mountain river in the Donghe watershed, China. A total of 34 sampling sites were sampled to study the spatial distribution of riparian plants among different stream orders. The results showed: Environmental factors among stream orders had significant differences. Among stream order, species richness showed remarkable differences. The species richness rose firstly and dropped afterwards except for tree species richness; tree species richness decreased while stream order increased. The same is true for shrub quadrat species richness. Shannon-Wiener diversity, Simpson dominance and Pielou uniformity showed significant difference among stream orders; Shannon-Wiener diversity rose firstly then dropped afterwards. For integrated environmental factors and community characteristics, we found the changes of stream orders had a significant impact on riparian habitats and riparian vegetation. Further analysis showed that riparian vegetation experienced different types and degrees of disturbance in different stream orders. This meant that a hierarchical management strategy should be applied to riparian vegetation management.

scholarly journals Native forests but not agroforestry systems preserve arbuscular mycorrhizal fungal species richness in southern Ethiopia

Mycorrhiza ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 749-759
Author(s):  
Zerihun Belay ◽  
Mesele Negash ◽  
Janne Kaseva ◽  
Mauritz Vestberg ◽  
Helena Kahiluoto
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Species Composition ◽  
Arbuscular Mycorrhizal ◽  
Soil Samples ◽  
Southern Ethiopia ◽  
Native Forest ◽  
Native Forests ◽  
Land Use Types ◽  
The Impact

Abstract The rapid conversion of native forests to farmland in Ethiopia, the cradle of biodiversity, threatens the diversity of the arbuscular mycorrhizal fungi (AMF) pivotal to plant nutrition and carbon sequestration. This study aimed to investigate the impact of this land-use change on the AMF species composition and diversity in southern Ethiopia. Soil samples were collected from nine plots in each of three land-use types: native forest, agroforestry, and khat monocropping. The plots of the three land-use types were located adjacent to each other for each of the nine replicates. Three 10 × 10m subplots per plot were sampled. AMF spores were extracted from the soil samples, spore densities were determined, and species composition and diversity were evaluated through morphological analysis. Both spore density and species richness were statistically significantly higher in the native forest than in the agroforestry plots with no clear difference to khat, whereas the true diversity (exponential of Shannon–Wiener diversity index) did not differ among the three land-use types due to high evenness among the species in agroforestry. In total, 37 AMF morphotypes belonging to 12 genera in Glomeromycota were found, dominated by members of the genera Acaulospora and Glomus. The highest isolation frequency index (78%) was recorded for Acaulospora koskei from native forest. Consequently, the agroforestry system did not appear to aid in preserving the AMF species richness of native forests relative to perennial monocropping, such as khat cultivation. In contrast, the native forest areas can serve as in situ genetic reserves of mycorrhizal symbionts adapted to the local vegetative, edaphic, and microbial conditions.

scholarly journals Encouraging farm gate sales and marketing through land use policy

2021 ◽  
Author(s):  
Heather Britten
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Food System ◽  
Local Food ◽  
Small Scale ◽  
Southern Ontario ◽  
Local Food System ◽  
Dynamic Relationship ◽  
Sales And Marketing ◽  
The Impact

This research brings together concepts of sustainability, a local food system, and farm gate marketing. With these concepts, the research explores two scales of policy planning with regards to land use in Ontario, and answers the question: In Southern Ontario, what is the impact of land use on a farmer's ability to sell at the farm gate? Despite the seemingly simple and small-scale nature of a farmer selling his/her produce at their own farm gate, there is surprising complexity to the myriad policies that apply. The dynamic relationship between eaters, farmer, and planners presents particularly interesting challenges for planners in Southern Ontario. Understand [sic] the local food system and engaging in local food consumption begins to address larger issues of sustainability and farm viability. By providing farmers with opportunities, through land use planning policy, they are able to engage with eaters at the farm gate and accomplish place-making activities.

scholarly journals Impact Evaluation of Artisanal and Small-Scale Mining on Land Use Land Cover: Implication for Sustainable Mining Environment in Niger State, Nigeria

2021 ◽  
Author(s):  
H.M Liman ◽  
N.G Obaje ◽  
P. Nwaerema
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Water Body ◽  
Policy Framework ◽  
Small Scale ◽  
Land Use Land Cover ◽  
Sustainable Mining ◽  
Mining Sites ◽  
Mining Environment ◽  
The Impact

This study evaluated the impact of artisanal and small-scale mining on land use land cover as it applies to sustainable mining environment in Niger State, Nigeria. Thus, thirteen different mining locations covering the three geo-political locations were geo-referenced. The satellite imagery of Landsat TM and EMT+ from Global Land Cover Facilities (GLCF) and Earth Explorer (EE) for tri-images (1994, 2004 and 2014) at 30m resolution was obtained to establish the changes that occurred over the study years. Landsat imageries were analyzed with the aid of computer-based GIS ILWIS 3.3. The imageries were classified into degraded land, settlement, vegetation and water body. Results showed that in 1994, 33.4% of the land use was degraded due to mining, settlement accounted for 3.7% and vegetation covered 59.2%. In 2004, 21.1% of the land was degraded, vegetation decreased from 59.2% in 1994 to 30.9% in 2004. In 2014, land degraded to 47.36%, settlement expanded to 16.06%, vegetation covered 24.22% and water body occupied 12.37% of the mining sites. Within the study period, mining sites increased from 30,000km2 (33%) to 48,000km2 (45%) indicating the severity of mining impact. Therefore, the government should develop strategic mining policy framework targeting a sustainable mining operation in Niger State. Keywords: Mining Effects, Artisanal mining, Environment, Land degradation, Niger State.

scholarly journals Complex Small-Holder Agriculture in Rainforest Buffer Zone, Sri Lanka, Supports Endemic Birds

2021 ◽  
Vol 9 ◽  
Author(s):  
Juliana Hanle ◽  
Balangoda M. P. Singhakumara ◽  
Mark S. Ashton
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Sri Lanka ◽  
Buffer Zone ◽  
Small Scale ◽  
Forest Fragments ◽  
Buffer Zones ◽  
Bird Abundance ◽  
Point Counts ◽  
Zone Management

The Sinharaja rainforest in southwestern Sri Lanka is a protected forest in a largely agriculture-dominated landscape. In keeping with global UNESCO global biosphere reserves planning, the Sinharaja is surrounded by a buffer zone of regenerating forest and villages with small tea plots and multi-strata tree gardens (homegardens). Globally, however, conservation planning lacks standards on buffer zone management. We ask what relationships exist between village land use and bird assemblages, which are effective ecosystem indicators. Birds have been little studied across land use and vegetation structure in actively managed, large, protected forest buffer zones. To that end, we ran spatially- and temporally-replicated bird point counts across tree gardens, forest fragments, and tea plots within a Sinharaja village. Tree gardens held a greater abundance of birds across habitat association, conservation concern, diet, and endemic species than forest fragments or tea plots. Forest fragments and tree gardens hosted statistically similar numbers of birds in some subsets, but their species assemblages differed. In tea plots, greater shade tree species richness correlated with greater bird abundance and species richness. Our results support the argument for programs to support complex small-scale tree-based agroforestry embedded in buffer zone regenerating forest.

scholarly journals Encouraging farm gate sales and marketing through land use policy

2021 ◽  
Author(s):  
Heather Britten
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Food System ◽  
Local Food ◽  
Small Scale ◽  
Southern Ontario ◽  
Local Food System ◽  
Dynamic Relationship ◽  
Sales And Marketing ◽  
The Impact

This research brings together concepts of sustainability, a local food system, and farm gate marketing. With these concepts, the research explores two scales of policy planning with regards to land use in Ontario, and answers the question: In Southern Ontario, what is the impact of land use on a farmer's ability to sell at the farm gate? Despite the seemingly simple and small-scale nature of a farmer selling his/her produce at their own farm gate, there is surprising complexity to the myriad policies that apply. The dynamic relationship between eaters, farmer, and planners presents particularly interesting challenges for planners in Southern Ontario. Understand [sic] the local food system and engaging in local food consumption begins to address larger issues of sustainability and farm viability. By providing farmers with opportunities, through land use planning policy, they are able to engage with eaters at the farm gate and accomplish place-making activities.

scholarly journals Agricultural expansion in African savannas – effects on diversity and composition of trees and mammals

2021 ◽  
Author(s):  
Hemant Tripathi ◽  
Emily Woollen ◽  
Mariana Carvalho ◽  
Catherine Parr ◽  
Casey Ryan
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Land Use Change ◽  
Biodiversity Loss ◽  
Small Scale ◽  
Agricultural Expansion ◽  
Miombo Woodlands ◽  
Mammal Species ◽  
Β Diversity ◽  
Impact On Biodiversity

Abstract Land use change (LUC) is the leading cause of biodiversity loss worldwide. However, the global understanding of LUC's impact on biodiversity is mainly based on comparisons of land use endpoints (habitat vs non-habitat) in forest ecosystems. Hence, it may not generalise to savannas, which are ecologically distinct from forests, as they are inherently patchy, and disturbance adapted. Endpoint comparisons also cannot inform the management of intermediate mosaic landscapes. We aim to address these gaps by investigating species- and community-level responses of mammals and trees along a gradient of small scale agricultural expansion in the miombo woodlands of northern Mozambique. Thus, the case study represents the most common pathway of LUC and biodiversity change in the world's largest savanna. Tree abundance, mammal occupancy, and tree- and mammal-species richness showed a non-linear relationship with agricultural expansion (characterised by the Land Division Index, LDI). These occurrence and diversity metrics increased at intermediate LDI (0.3 to 0.7), started decreasing beyond LDI > 0.7, and underwent high levels of decline at extreme levels of agricultural expansion (LDI > 0.9). Despite similarities in species richness responses, the two taxonomic groups showed contrasting β-diversity patterns in response to increasing LDI: increased dissimilarity among tree communities (heterogenisation) and high similarity among mammals (homogenisation). Our analysis along a gradient of landscape-scale land use intensification allows a novel understanding of the impacts of different levels of land conversion, which can help guide land use and restoration policy. Biodiversity loss in this miombo landscape was lower than would be inferred from existing global syntheses of biodiversity-land use relations for Africa or the tropics, probably because such syntheses take a fully converted landscape as the endpoint. As, currently, most African savanna landscapes are a mosaic of savanna habitats and small scale agriculture, biodiversity loss is probably lower than in current global estimates, albeit with a trend towards further conversion. However, at extreme levels of land use change (LDI > 0.9 or < 15% habitat cover) miombo biodiversity appears to be more sensitive to LUC than inferred from the meta-analyses. To mitigate the worst effects of land use on biodiversity, our results suggest that miombo landscapes should retain > 25% habitat cover and avoid LDI > 0.75 – after which species richness of both groups begin to decline. Our findings indicate that tree diversity may be easier to restore from natural restoration than mammal diversity, which became spatially homogeneous.

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